Less than a month before the Apollo 1 was supposed to land on the moon, it caught fire during a launch rehearsal on January 27, 1967. It killed all three of its crew members. Whoa.

Turns out the fire was caused by a whole bunch of design and calculation errors on the part of NASA, meaning the astronauts' deaths could have been prevented. Double whoa.

In an attempt to prevent future fatal blunders, NASA Flight Director Eugene Kranz delivered a "shape up or ship out"-style speech to his staff about their responsibilities to the safety and well-being of the astronauts. He urged his team of ground controllers to be "tough and competent," and not let something like Apollo 1 happen again because of carelessness.

Sadly, Kranz's words didn't put an end to all space flight disasters, but the gist of his message to be as thorough and rigorous as possible became core values of NASA's workforce.

So when an accident like the Challenger Disaster occurs, it prompts the question: who wasn't as tough or as competent as they should have been?